Grease pencil black circles
I believe those are the "lookdev preview spheres" as I like to call them. They appear in the same spot as your screenshot when in the shading tab in a default file. In a shellnut they show some basic lighting on a default sphere, and a HDRI if set up with one. I believe they are rendering as black circles because you don't have lighting in your scene or something funky is happening with some lighting settings, leaving them as spheres of solid shadow.

These spheres will not render in your final output, so if you're fine with them being there, you can stop here.

However, if you want to get rid of them, you can change your rendering mode from lookdev to anything else. I haven't found a checkbox to get rid of them completely yet, but there is a setting to make them smaller. You can change the lookdev spheres size in the panel accessed by clicking the settings cog that appears under a dropdown menu in the top right corner of your viewport.


TL;DR: The circles won't render, so you can ignore them, but if you want them smaller you can turn down the sphere size.